Left 4 Dead 2 + Prima Official Strategy Guide

It's all go at Payday: The Heist developer Overkill Software these days. As well as working on a sequel and DLC for its coop crime caper FPS, and being acquired by Starbreeze Studios, the Swedes have revealed they're working with Valve on something Left 4 Dead-y.

"We are excited to be able to confirm that an in-depth collaboration between Overkill and Valve is currently in production," Overkill game director Ulf Andersson said in a statement (via VG247).

"We are working on a very cool blend of Payday and Left 4 Dead. I am sure it is so exciting that it will have some players check into the hospital before we are done."

As for what this'll actually be, who knows? Payday clearly took a few hints from Valve's zombie 'em up, so it wouldn't be too jarring for the worlds to collide. Valve characters often make appearances in other games, but that probably wouldn't meet the "in-depth" requirement. Might that mention of the hospital be a cheeky nod to Left 4 Dead's 'No Mercy' campaign, set around an overrun hospital?

The original group of Starbreeze has three projects in the works itself.

It seems like Valve is committed to bringing its prized digital distribution service Steam to Linux users at some point in the relatively near future. Recent news indicates that Valve has not only hired Linux developers to help port Steam and the Source engine to the OS, but Valve's Gabe Newell is now overseeing the port.

Phronoix.com's Michael Larabel recently spoke with Newell about the porting process, and claims that Steam will become available for Linux in the next few months.

"Gabe's vision to support, embrace, and promote Linux are amazing, assuming they execute, which looks to be very high probability at this point," Larabel said. He goes on to state that although Linux development has been going on at Valve for some time, Newell's personal involvement in the project (including relocating his desk to the Valve Linux Development camp), bodes well for the project reaching critical mass more quickly.

As far as the Source Engine port goes, Left 4 Dead 2 is being used as the test case, largely due to the solid nature of the game's code. Despite a few snags, Larabel asserts that the project is moving along at a good clip, and notes that the developer's flat management structure is at least partly responsible for contributing to delays in the port's development.

Larabel also claims that Newell isn't a big fan of the nearly ubiquitous operating systems like Windows or OSX, or the upcoming Windows 8, in particular. "His level of Linux interest and commitment was incredible while his negativity for Windows 8 and the future of Microsoft was stunning," Larabel said of his meeting with Newell.

While it's reasonable to assume that a number of folks will be excited about finally getting some Steam in their Linux, the port of the OS could have larger implications. For example, one needs only look as far as the news that Valve has been exploring the possibility of creating some new gaming hardware and wearable computers.

When Left 4 Dead first introduced its new brand of co-operative zombie-slaying, it didn't take long for a rabid fan-base to develop. In a recent interview, several Left 4 Dead luminaries, including writer Chet Faliszek and then-Turtle Rock CEO Mike Booth, reminisced about how the Left 4 Dead series came to be.

Left 4 Dead and Left 4 Dead 2

The team revealed that Left 4 Dead's DNA actually came from a Counter-Strike mod. Shortly after Turtle Rock Studios had shipped Counter-Strike: Condition Zero in 2004, CEO Mike Booth showed a mod called Terror Strike--ostensibly a never-ending zombie-attack mode on the CS_Italy map--to Faliszek and Erik Wolpaw, who both fell in-love with the concept. Later that day, Valve CEO Gabe Newell conscripted Faliszek and Wolpaw to team up with Booth's Turtle Rock (purchased by Valve in 2008) to develop the concept further. Early in development, Booth explained that the team understood they "had this nugget of gameplay where a small co-operative group had to deal with hundreds of melee monsters."

Years of playtesting and iteration helped the team focus on trying to create an experience for players that was both "emergent and yet structured." Out of this focus came the game's procedural population system, which constantly adds and removes zombies from the game world to create the illusion of never-ending hordes of the undead. (The first game only allowed 30 on-screen zombies at a time.) According to Booth, the zombies' non-aggressive ambient behavior (such as when they're just standing or laying around) was also based on fears brought about by the potential 2005 bird-flu pandemic.

Booth clarified:

We kind of pushed on that with the wandering infected, how they stumble around and vomit and just look like they're having the worst flu ever. We wanted that combination of pity and 'it could be meâ with 'this is horrible' and then 'Oh my God, here they come, we have to survive.'

The game's now-famous AI-director--which modulates when and where zombies and item pickups will appear, based on a real-time assessment of player performance--was also created in aid of a more dynamic, less predictable experience. Booth explained how Left 4 Dead's AI-director evolved along with the series:

We needed to make sure that certain tempos and pacing happened on a regular basis to keep people's excitement and attention going. For L4D that was basically just me and some C++ code making that happen. In L4D2 we generalised it into a larger tools framework.

The Left 4 Dead retrospective, which also touches on competitive multiplayer and how the team designed the game to encourage players to cooperate in a world where co-op was still a relative rarity, can be found here.

Valve's quest to inject original Left 4 Dead episodes into Left 4 Dead 2 continues. Today's Left 4 Dead 2 update includes the new version of the Terminal Map for Dead Air, the game's official blog revealed.

To entice people to test the update, the team at Valve is offering players a prize: the beta version of the Blood Harvest campaign for Left 4 Dead 2. Getting the prize won't be easy, however, as players will have to accomplish a difficult task together.

Left 4 Dead 2

A new achievement, dubbed "Connecting Flights," has been added to Left 4 Dead 2, which unlocks when players play "a complete game of Versus in Dead Air." When 60,000 people have earned the achievement, Valve will unlock the beta version of Blood Harvest on Steam "the next weekday."

Previously, Valve offered to unlock Dead Air early, if 20,000 L4D2 players unlocked a freshly created achievement. A mere 24 hours later, the goal was shattered.

This time, Valve is making it harder to accomplish the goal. "60,000 is going to be hard," the official blog noted. "You canât rage quit and you need to work together. Once you get the achievement, help others get it as well."

Valve has been making comics around some of its biggest properties for months for free online, but now the company has partnered with Dark Horse Comics to bring them out in print. Comic Book Resources (via Gamasutra) reports that "Valve Presents: The Sacrifice and Other Steam-Powered Stories" will go on sale November 16 for $29.99.

The collection is a bit pricier than the average comic collection, but it's also more than three-hundred pages long and sports a hardcover. That makes it hard to complain. It will include stories from the worlds of Team Fortress 2, Portal, and Left 4 Dead. All indications are that this is a compilation of comics you can already find online, but it wouldn't surprise us if Valve slipped a bonus or two in there.

Last week, Valve promised to release the Left 4 Dead 2 version of classic Left 4 Dead episode 'Dead Air' if players helped beta test new community-made map Cold Stream, setting a target for 20,000 playthroughs. Good news! "You started playing at 10am on Wednesday morning. Four and half hours later you surpassed the 20,000 target," Valve revealed in a blog post. "By 5pm you passed 30,000. By this morning at 10am â" a mere 24 hours later you hit 60,774!"

The original Dead Air in Left 4 Dead

"We are going to try and release it as early as possible but will release it on July 22nd the latest," Valve said. "It isn't currently ready for release as we have been working on The Terminal and Finale maps and need to test them more internally."

The developer also mentions working on a new version of the finale in L4D2's 'Dead Carnival' episode, "and some gameplay changes for finales in general." As ever, the changes will hit PC and Mac first.

Once the changes have been given a good testing, and Cold Stream and the rest of the original L4D episodes are finished, it'll all head over to Xbox 360 too. "What date is that?" Valve asks. "Hard to say but with your help it just got closer."

Once again, Valve is offering early access to a game if its fans jump through a hoop or two. This time it's Left 4 Dead 2, and the offer is a piece of the Cold Stream downloadable content. A blog post outlines the details.

The developer is currently in the testing phase, and is offering an incentive for the community to become bug-finders. If 20,000 people earn the "Stream Crosser" achievement by the end of the day on Sunday, July 10, Valve will release Dead Air (from Cold Stream) on July 22. Stream Crosser is awarded for surviving a campaign of Cold Stream, so it shouldn't be too unobtainable. If you don't own the game yet, it's just $5 until 10 am PST today.

Valve previously offered early access to Portal 2 in exchange for playing indie games. This netted users the anticipated game about 9 hours early. Unlocking DLC for an existing game probably isn't quite as exciting, but early is early.

A new Left 4 Dead 2 downloadable content pack is in the works, developer Valve has announced, featuring the three remaining Left 4 Dead campaigns that have yet to be ported over to the sequel as well as a new community-made campaign.

Valve is also soliciting opinions and suggestions from players. The work-in-progress campaign will be available for all to play "in the next few weeks," and a forum has been set up for feedback and suggestions. Valve explains that following the story-heavy DLCs The Passing and The Sacrifice, this new pack will add no new story or audio, so if you have an idea which calls for neither, head on over to the forum and suggest away.

The yet-unnamed DLC will be released for PC, Mac and Xbox 360 "sometime after Portal 2," which launches on April 20. Valve says that it will be subject to "Valve Time," the process whereby projects take as long as they take rather than being rushed to deadlines, noting that this "is a good thing, not a bad thing."

Left 4 Dead's new DLC, 'The Sacrifice,' launched today, and in a move that's as much awesome as it is likely to cause some Xbox RAGE, Valve is selling both titles on Steam for a deep discount. The Mac version of Left 4 Dead 2 went live today as well, for the same ultra-low price.

If you still haven't experienced the joys of shooting the undead with friends, the latest Steam sale is an awesome excuse. For the duration of the sale, Left 4 Dead and Left 4 Dead 2 can be purchased for a mere $6.79 each, or bundled together at an even deeper discount of $10.19. And of course, you get all of the delicious DLC with the PC and Mac versions for no extra charge, including 'The Sacrifice.'

Those playing the game on the Xbox 360 are also able to download 'The Sacrifice,' but it's 560 Microsoft Points ($7). In fact, when compared to the current Steam sale, it's more expensive to buy all of the console-based series' DLC than it is to purchase both full games (which include all DLC for free) for either PC or Mac.

The latest downloadable content for Left 4 Dead 2 (and presumably last for the original) is set to launch next week. "The Sacrifice" DLC follows the original Left 4 Dead cast as they journey South, losing one of their own team members along the way.

While there is one real conclusion to the story, as evidenced in the previous DLC "The Passing," players will have the opportunity to re-write history and select which team member will fall in "The Sacrifice." It won't change the franchise's canon, but it'll make you look totally badass.